Fundamentals of Ecology & Ecosystems MCQ Questions
Ques:
51
The amount of energy during the transfer from one trophic level to another in an eco-system–
Correct Answer:
(B)
Decreases
Energy is the basic force responsible for all metabolic activities. The flow of energy from producer to top consumers is called energy flow, which is unidirectional. Energy flows through the trophic levels i.e. from producers to subsequent trophic levels. This energy always flows from lower (producer) to higher (herbivore, carnivore, etc.) trophic level. There is a loss of some energy in the form of unusable heat at each trophic level so the amount of energy during the transfer from one trophic level to another decreases in an ecosystem.
Ques:
52
Consider the following statements regarding energy flow:
1. Every trophic level sees about 90% energy loss, underscoring nature’s efficiency limits.
2. Unidirectional energy flows in one direction from producers to top consumers with recycling of the energy itself.
Which of the statements given above is/are correct?
Correct Answer:
(A)
1 only
Energy Flow
Sunlight Efficiency: Despite the sun’s immense energy, only 2–10% of the Photosynthetically Active Radiation is used by plants.
Energy Loss: Every trophic level sees about 90% energy loss, underscoring nature’s efficiency limits.
Unidirectional Flow: Energy flows in one direction—from producers to top consumers—with no recycling of the energy itself.
Ques:
53
The energy flow in an ecosystem is
Correct Answer:
(B)
Unidirectional
The flow of energy in an ecosystem is unidirectional, meaning it moves in one direction only. This occurs because energy is lost as heat during metabolism and other processes, and this lost energy cannot be reused by producers (like plants) for photosynthesis.
Ques:
54
In a food chain, man is:
Correct Answer:
(D)
Primary as well as a secondary consumer
In food chain there are trophic levels i.e., Autotroph, Primary consumer, Secondary consumer and Tertiary consumer. The primary consumer is the herbivores (that feed on the plant), the secondary consumer is small carnivores (feeding on primary consumer) and the tertiary consumer is larger carnivores. So, in food chain, man is the primary as well as a secondary consumer who feeds on both plant, products and meat.
Ques:
55
Concerning food chains in ecosystems, consider the following statements
A food chain illustrates the order in which a chain of organisms feeds upon each other.
Food chains are found within the population of a species.
A food chain illustrates the number of organism, which is eaten by others.
Which of the statements given above is /are correct?
Correct Answer:
(A)
Only 1
Now most obvious aspect of nature is that energy must pass from one living organism to another. When herbivorous animals feed on plants, energy is transferred from plants to animals. In an ecosystem, some of the animals feed on other living organisms while some feed on dead organic matter. The latter form the detritus food chain. Each chain usually has only four to five such links. Food chains are not found within the population of a species. Because this would mean a human being eating another human being (human beings are single species)
Note: The correct order of a common marine food chain is –
Diatom → Crustaceans → Herrings
Ques:
56
The correct order in the food chain of the various components of a terrestrial grass ecosystem is –
Correct Answer:
(A)
Grass, Grasshopper, Frog, Snake
Any substance consumed to provide nutritional support for an organism is called food. Plants are self-feeding and make for their own food whereas animals depend on plants for food. Food chain depicts the flow of energy through different organisms in an ecosystem. Notably, this flow is unidirectional. The correct order of different components in the above food chain is as follows:
Grass → Grasshopper → Frog → Snake
↓ ↓ ↓ ↓
(Producer) (Primary Consumer) (Secondary Consumer) (Tertiary Consumer)
Ques:
57
Which one of the following organisms is likely to show the highest concentration of DDT, once it has been introduced into the ecosystem?
Correct Answer:
(C)
Snake
DDT is a non-biodegradable, biomagnifying pollutant which increases in concentration from producers, primary consumers, secondary consumers to tertiary consumers. In the question, only the snake represents the tertiary consumers, so the concentration of DDT will be highest in the snake.
Ques:
58
Consider the following statements regarding Food Web:
1. Here an organism of higher level trophic feeds on a specific organism of lower trophic level.
2. Food web has a role in improving the adaptability and competitiveness of an organism.
Which of the statements given above is/are correct?
Correct Answer:
(B)
2 only
In Food web is a multitude of networks showing the flow of energy. Here an organism of a higher trophic level has access to more members of a lower trophic level. It has a role in improving the adaptability and competitiveness of an organism.
In Food chain, an organism of higher level trophic feeds on a specific organism of lower trophic level.
Ques:
59
Which of the following best describes the flow of energy in a food web?
Correct Answer:
(A)
a) From producers to consumers, then to decomposers.
In a food web, energy flows from producers to consumers, and then ultimately to decomposers. Producers, like plants, capture energy from the sun through photosynthesis and convert it into chemical energy, which is then transferred to consumers when they eat the plants. These consumers, which can be herbivores, carnivores, or omnivores, obtain energy by consuming other organisms. Finally, when organisms die, decomposers, like bacteria and fungi, break down the organic matter and release nutrients back into the environment, completing the cycle.
Ques:
60
Which of the following is correct sequence of ecosystem in order of decreasing productivity?
Correct Answer:
(C)
Mangroves, Grasslands, Lakes and Oceans
The correct sequence of ecosystem in order of decreasing productivity is- Mangroves, Grasslands, Lakes and Oceans. Despite occupying about 70 percent of the surface, the productivity of the oceans are only 55 billion tons. Hence option (c) is correct.